Growth of knowledge

A term coined by Karl Popper in his famous work The Logic of Scientific Discovery to denote what he regarded as the main problem of methodology and the philosophy of science, i.e. to explain and promote the further growth of scientific knowledge. To this purpose, Popper advocated his theory of falsifiability, testability and testing.^[1]

The 20th century was a triumph for human health and longevity. An Indian born in 1900 had a life expectancy of 22 years; an American baby born that year could expect to live about 49 years. By century’s end life expectancy had soared to unprecedented levels even in many poor countries. In 2005, average life expectancy at birth in the United States was 78 years; in India it was 62 years.

1. 1. The falling death toll from infectious diseases—primarily among infants and young children—led to these

spectacular improvements in human life expectancy. For most of human history, communicable diseases such as malaria, smallpox, and tuberculosis (TB) were leading causes of death. TB was the second-highest cause of death in the United States in 1900, and malaria was a major problem in southeastern U.S. states. These diseases were effectively controlled in the United States and declined throughout much of the world in the 20th century. One major disease—smallpox—was virtually wiped out; another—polio—may be close to eradication.

1. 2. Improvements in sanitation and the development of vaccines and antibiotics accelerated the decline of infectious and parasitic diseases (IPDs) in the 20th century. But, with a few exceptions, communicable diseases have not been vanquished. The microbes that cause these diseases continue to evolve, sometimes requiring new drugs and methods to combat them. New pathogens emerge, or make the jump from infecting animals to infecting humans. The most recent global estimates show that communicable diseases cause about one-third of all deaths (see Figure 1). Pneumonia and other lower respiratory diseases are the largest group, followed by HIV/AIDS, diarrheal diseases, TB, and malaria. Communicable diseases impose vastly different health burdens on the wealthy and poor. They are the primary reason why a baby born in Somalia today is 30 times more likely to die in infancy than a baby born in France.

1. 3. Most of these diseases—including measles, HIV, TB, and malaria—are preventable and treatable using proven and often surprisingly low-cost health interventions. But control of communicable diseases will require additional financial investments, fundamental improvements in health delivery, and longer-term political commitments.

1. 4.

See also

• Falsification

References